Trace ruthenium dioxide stabilize active center of CoFe-LDH for efficient water electrolysis.

It is immensely meaningful to design efficient electrolysis for water electrolysis and realize green hydrogen production. Herein, a ruthenium dioxide modified CoFe-Layered double hydroxides (LDHs) catalyst (RuO 2 /CoFe-LDH/NF) was synthesized by combining the advantages of RuO 2 and CoFe-LDHs for driving alkaline water and seawater. RuO 2 /CoFe-LDH/NF display impressive activity and stability at 10 mA cm−2, which only need an overpotential of 59 and 270 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) respectively. Meaningfully, the catalyst only required a small cell voltage of 1.58 V as a bifunctional catalyst, what is superior to commercial RuO 2 /NF||Pt/C/NF (1.66 V). In addition, RuO 2 /CoFe-LDH/NF exhibited excellent HER and OER performance with overpotentials of 119 and 260 mv in alkaline seawater at 10 mA cm−2, respectively. Additionally, RuO 2 /CoFe-LDH/NF displays a larger corrosion potential, smaller corrosion and improved oxygen evolution capacity than CoFe-LDH/NF. Moreover, there is electron transfer between Ru and Co or Fe, which can improve the micro-coordination environment and enhance the stability for RuO 2 /CoFe-LDH/NF. The method with integration of RuO 2 and CoFe-LDH could be broadened to explore other robust bifunctional catalysts for water/seawater electrolysis. Trace RuO 2 decorated CoFe-LDH can not only provide much more active sites, but also stabilize the active site of CoFe-LDH, resulting in an enhance activity and stability [Display omitted] • RuO 2 nanoparticles modified CoFe-LDHs were prepared by a simple hydrothermal synthesis method. • RuO 2 /CoFe-LDH/NF displays excellent HER and OER performance in seawater electrolysis. • The interaction among various metals can establish a micro-environment to enhance stability. [ABSTRACT FROM AUTHOR]